A new medicine that could stop or even prevent arthritis offers the prospect of a genuine breakthrough in the treatment of the illness.
Using cells that regulate the body's immune system, scientists have created an "infusion" that stops the "cascade of inflammations" to joins and body tissue caused by the illness.
An Arthritis Research UK spokeswoman said that tests showed that the new infusion halted development of the disease when used with methotrexate, a commonly used treatment.
This has raised hopes that it could be used to combat the causes of the disease rather than just mask its symptoms.
The most widely used treatments for rheumatoid arthritis merely mitigate joint damage and slow the illness's progress, and can have unpleasant side-effects.
Experts at the Dana-Farber Cancer Institute in Boston, Massachusetts, where tests are being conducted, believe that the treatment could be revolutionary.
Dr Harvey Cantor said: "We found we could almost completely inhibit the disease in this setting."
Using T regulatory cells, or Tregs, that regulate the body's immune response, the treatment prevents the immune response attacking the joints.
Tregs are a type of white blood cell that stop an immune reaction when a body has successfully fought off an attack from, for example, a virus or bacteria.
Arthritis is an autoimmune disease, which means that the immune system attacks healthy parts of the body.
Trials on mice reported in the Journal of Clinical Investigation have so far have been successful.
It is estimated that 10 million people in the UK suffer from arthritis, which causes painful swelling of the joints, as well as fatigue and disability.
Arthritis Research UK said: "The data from laboratory experiments is promising, However, this research is in the early stages and has not yet been developed into a treatment that can be tested in clinical trials."